Questions on Algebra: Sequences of numbers, series and how to sum them answered by real tutors!

Tutors Answer Your Questions about Sequences-and-series (FREE)

Question 843121: Find the number of terms in this sequence 12;7;2;....-203
Click here to see answer by ewatrrr(24785)

Question 843163: sequence is: -3/4 ; X ; Y ; 2/9
question is: determine the values of X and Y so that the sequence is geometric.
Click here to see answer by ewatrrr(24785)

Question 843122: 3,6,12,24
Click here to see answer by Fombitz(32388)

Question 843238: 3,-6,12,4,20 Answers: 13,14,6,16
7,16,8,27,9 Answers: 27,10,40,37
7,21,8,72,9 Answers: 81,243,123,136
2,7,26,101,400 Answers: 15,95,800,695,1840
Click here to see answer by richard1234(7193)

Question 843285: Write a formula for the nth term for the sequence below:
2/5, 4/6, 6/7, 8/8, ...
I sort of know how to set it up. Just having a problem finding the difference.
a(n)= 2/5* [?] ^(n-1)
thanks :)
Click here to see answer by LinnW(1048)

Question 843439: Subhash can copy 50 pages in 10 hours.subhash and prakash together can copy 300 pages in 40 hours.in how much time can prakash copy 30 pages?with process
Click here to see answer by ayushk(2)

Question 843458: -the 4th term of an AP is 7 and the 9th term is 17 find the 15th term ??
-if 4 times the 4th term of an AP is equal to 7 times the 7th term,find its 11th term

Click here to see answer by TheInstructor(29)

Question 840618: Determine the 30th term of the sequence -10, -15, -20...
Click here to see answer by TheInstructor(29)

Question 843510: An engineer undertakes a project to build a road of 15 km long in 300 days and employs 45 men for the purpose.after 100 days he finds only 2.5 km of the road has been completed.find the number of extra men he must employ to finish the work in time.with process.
Click here to see answer by richwmiller(17219)

Question 843550: X+3;2x+6;3x+9;.....determine the 10th term in terms of x and determine the nth tern in terms of x
Click here to see answer by ewatrrr(24785)

Question 843553: Consider the arithmetic series 2+5+8+11....and answer the question that follow ? State the values of T1 and S1
Click here to see answer by Fombitz(32388)

Question 843435: My problem is to find the indicated term for the geometric series described :
Sn=33 an=48 r=-2 , find a1.
I am trying to use the formula SN= a1-a1 r(n)/ 1-r
However, i am missing 2 variables both a1 and "n". I have tried to solve first using an=a1 r (n-1) but again, i am missing 2 variables (a1 and n).
Please tell me how to solve for a1. Thanks
Click here to see answer by Theo(13342)

Question 843603: Three pipes A,B and C in a tank. They can fill the tank in 10 hrs, 20 hrs and 25 hrs respectively.
At first all of them are opened simultaneously.
After 2 hrs,tap C is closed and A and B are kept running.
After 4 hrs, tap B is also closed. The remaining work is done by Tap A alone.
Find the percentage of the work done by Tap A by itself.
Click here to see answer by Azeez majiyagbe(1)

Question 843681: Next number in sequence. 1, 5, 17, 53, 161
Click here to see answer by ewatrrr(24785)

Question 843786: Question-Find the fifth, tenth, and hundredth terms of each sequence? numbers given- 4,14,24,34?
Click here to see answer by Fombitz(32388)

Question 844019: fing the missing term in the arithemetic sequence
55,_,_,_,155
Click here to see answer by stanbon(75887)

Question 844019: fing the missing term in the arithemetic sequence
55,_,_,_,155
Click here to see answer by richwmiller(17219)

Question 844013: the sum of the 3 terms of an A.P is 9 and the sum of the next 2 terms is 16.List the first 6 terms
Click here to see answer by stanbon(75887)

Question 844022: Write an arithmetic series with seven terms such that the sum of the series is 64
Click here to see answer by fcabanski(1391)

Question 844022: Write an arithmetic series with seven terms such that the sum of the series is 64
Click here to see answer by stanbon(75887)

Question 843411: 1+2+4+8+16+32+...+65,536 Find the sum of each sequence of numbers. Help?
Click here to see answer by KMST(5328)

Question 844162: how do you figure this problem out
3+ + 136 = 1690
Click here to see answer by Alan3354(69443)

Question 844205: Write the first four terms of the sequence. a1 = 13 and an = an-1 + 8 for n ≥2?
Click here to see answer by Fombitz(32388)

Question 844309: (Can someone please help me with this question?)
The sum of two numbers is 3. Four times the larger number plus three times the smaller number is 25. Find the numbers.
The larger number is___?
and the smaller number is___?
Click here to see answer by josmiceli(19441)

Question 844299: If told that the 3rd term of an GP is 45 and the 6th term is 1215 find the first term and the common ration?
Click here to see answer by Alan3354(69443)

Question 844224: if a,b,c are in HP and ab + bc + ca = 15 then ca =

Click here to see answer by Edwin McCravy(20056)

Question 844478: what is the sum of all of these? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
isnt there like a technique? :D
Click here to see answer by Fombitz(32388)

Question 844478: what is the sum of all of these? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
isnt there like a technique? :D
Click here to see answer by Alan3354(69443)

Question 844870: The eighth term of the expansion (2c+d)^7
The first term of the expansion of (3q-7r)^6
The second term of the expansion of (a+3b)^10

Click here to see answer by Edwin McCravy(20056)

Question 844736: what is the next number in the sequence 3,-6,12,4,20, ?
Click here to see answer by Edwin McCravy(20056)

Question 844979: 2^(3n-2)
Click here to see answer by Fombitz(32388)

Question 844510: Each term of sequence is determined by adding half to the preceding term.The sum of the first twenty five terms of the sequence equals the square of the twenty fifth term.How can I calculate the possible value(4) of the first term?
Click here to see answer by Edwin McCravy(20056)

Question 845219: Which fraction is the greatest: 15/30, 4/15, 3/48, or 12/36?

Click here to see answer by Edwin McCravy(20056)

Question 846038: if a,b ,c. are in HP. then prove that a/c =d-c/b -c
Click here to see answer by psbhowmick(878)

Question 846222: What is the next fraction in this sequence? Simplify your answer.
13/15 , 4/5 , 11/15 , 2/3
Click here to see answer by josmiceli(19441)

Question 846414: X=1,2,3,4,5
Y=2,_,_,_,162
For each geometric, find the missing term in the sequence
Click here to see answer by josgarithmetic(39618)

Question 846441: W/12 = 36
Click here to see answer by Fombitz(32388)

Question 846507: If the sequence is geometric, what is its common ratio?
-1, -4, -16, -64, ...
Click here to see answer by ewatrrr(24785)

Question 846566: find the commanon ratio of the sequence.
-125, -25, -5, -1,...
Click here to see answer by Fombitz(32388)

Question 846928: The first and last terms of an AP are 67 and 171 respectively. If
The first and last terms of an AP are 67 and 171 respectively. If there are 14 terms, find the 16th term of the AP
Click here to see answer by Theo(13342)

Question 846911: 13 - 5 x 2 - 4 squared = ?
Click here to see answer by Fombitz(32388)

Question 846949: The third term of an AP is ten more than the first term while the fifth term is 15 more than the second term. find the sum of the 8th and 15th term of the Ap if the 7th term is 7 times the first term.
Click here to see answer by Edwin McCravy(20056)

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860, 4861..4905, 4906..4950, 4951..4995, 4996..5040, 5041..5085, 5086..5130, 5131..5175, 5176..5220, 5221..5265, 5266..5310, 5311..5355, 5356..5400, 5401..5445, 5446..5490, 5491..5535, 5536..5580, 5581..5625, 5626..5670, 5671..5715, 5716..5760, 5761..5805, 5806..5850, 5851..5895, 5896..5940, 5941..5985, 5986..6030, 6031..6075, 6076..6120, 6121..6165, 6166..6210, 6211..6255, 6256..6300, 6301..6345, 6346..6390, 6391..6435, 6436..6480, 6481..6525, 6526..6570, 6571..6615, 6616..6660, 6661..6705, 6706..6750, 6751..6795, 6796..6840, 6841..6885, 6886..6930, 6931..6975, 6976..7020, 7021..7065, 7066..7110, 7111..7155, 7156..7200, 7201..7245, 7246..7290, 7291..7335, 7336..7380, 7381..7425, 7426..7470, 7471..7515, 7516..7560, 7561..7605, 7606..7650, 7651..7695, 7696..7740, 7741..7785, 7786..7830, 7831..7875, 7876..7920, 7921..7965, 7966..8010, 8011..8055, 8056..8100, 8101..8145, 8146..8190, 8191..8235, 8236..8280, 8281..8325, 8326..8370, 8371..8415, 8416..8460, 8461..8505, 8506..8550, 8551..8595, 8596..8640, 8641..8685, 8686..8730, 8731..8775, 8776..8820, 8821..8865, 8866..8910, 8911..8955, 8956..9000, 9001..9045, 9046..9090, 9091..9135, 9136..9180, 9181..9225, 9226..9270, 9271..9315, 9316..9360, 9361..9405, 9406..9450, 9451..9495, 9496..9540, 9541..9585, 9586..9630, 9631..9675, 9676..9720, 9721..9765, 9766..9810, 9811..9855, 9856..9900, 9901..9945, 9946..9990, 9991..10035, 10036..10080, 10081..10125, 10126..10170, 10171..10215, 10216..10260, 10261..10305, 10306..10350, 10351..10395, 10396..10440, 10441..10485, 10486..10530, 10531..10575, 10576..10620, 10621..10665, 10666..10710, 10711..10755, 10756..10800, 10801..10845, 10846..10890, 10891..10935, 10936..10980, 10981..11025, 11026..11070, 11071..11115, 11116..11160, 11161..11205, 11206..11250, 11251..11295, 11296..11340, 11341..11385, 11386..11430, 11431..11475, 11476..11520, 11521..11565, 11566..11610, 11611..11655, 11656..11700, 11701..11745, 11746..11790